1. Field of the Invention
This invention pertains to coiling, storage and uncoiling of large-diameter, heavy-wall pipe in long lengths.
2. Description of the Prior Art
The customary technique for storing large-diameter, heavy-wall pipe, particularly when laying the pipe on the ocean floor, is to take sections of pipe and weld them to the end of the pipe catenary. It has long been a problem in such practice to handle and weld the sections of pipe on the crowded deck of a ship.
Another storing technique is to coil the pipe on the vessel. Various patented techniques for coiling and uncoiling pipe are shown in U.S. Pat. Nos. 2,219,811; 3,116,781; 3,685,306; 3,680,342; 3,641,778; 3,512,367; 3,237,438; 3,372,461; 3,331,212; and 928,220 and British Pat. No. 601,103. U.S. Pat. No. 3,237,438, to Tesson, basically exemplary. The technique disclosed by the Tesson patent is basicaly to form a bend in the pipe approximately of the curvature of the average diameter of the coil on a reel and then to rotate the reel to pull the pipe onto the coil. The reel in such a technique must be driven and of great strength in order to pull the bent pipe into a firm coil on the reel, primarily since the bending occurs at a location spaced from the point of tangency of the coil.